48 lines
1.1 KiB
Lua
48 lines
1.1 KiB
Lua
-- ostro_mo5.lua : converts a color image into a
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-- TO9 image (320x200x16 with color clashes)
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-- using Ostromoukhov's error diffusion algorithm.
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--
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-- Version: 02-jan-2017
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--
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-- Copyright 2016-2017 by Samuel Devulder
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--
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-- This program is free software; you can redistribute
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-- it and/or modify it under the terms of the GNU
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-- General Public License as published by the Free
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-- Software Foundation; version 2 of the License.
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-- See <http://www.gnu.org/licenses/>
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run('lib/ostromoukhov.lua')
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run('lib/color_reduction.lua')
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OstroDither:new():dither40cols(function(w,h,getLinearPixel)
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local c16 = h==200 and w==320
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for y=0,h-1 do
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for x=0,w-1 do
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if getbackuppixel(x,y)>15 then c16 = false end
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end
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end
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local pal
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if c16 then
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pal = {}
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for i=0,15 do
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local r,g,b=getbackupcolor(i)
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r = thomson.levels.pc2to[r]
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g = thomson.levels.pc2to[g]
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b = thomson.levels.pc2to[b]
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pal[i+1] = r+g*16+b*256-273
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end
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else
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pal=ColorReducer:new():analyzeWithDither(w,h,
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getLinearPixel,
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function(y)
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thomson.info("Building palette...",math.floor(y*100/h),"%")
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end):boostBorderColors():buildPalette(16)
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end
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thomson.palette(0, pal)
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return pal
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end)
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